CX28394/28395/28398
3.0 Registers
Quad/x16/Octal—T1/E1/J1 Framers
3.12 Transmitter Registers
AUTO_AIS /TAIS
Manual/Automatic Transmit Alarm Indication Signal—When activated manually (TAIS) or
automatically (AUTO_AIS), the alarm formatter replaces all data output on
TPOSO/TNEGO/TNRZO with an unframed all ones signal (AIS). This includes replacing data
from the receiver during line loopback [LLOOP; addr 014]. Automatic mode sends AIS for the
duration of receive loss of signal [RLOS; addr 047]. If AISCLK [addr 075] is enabled, then
TAIS also provides manual switch control over ACKI clock input. AUTO_AIS does not affect
ACKI switching.
AIS transmission [TAIS, AUTO_AIS; addr 075, or AISCLK; addr 075] does not affect
transmit data that is looped back to the receiver during framer loopback [FLOOP; addr 014].
This allows both FLOOP and LLOOP to be active simultaneously, during a loss of signal,
without disrupting data in the framer loopback path.
TAIS AUTO_AIS AISCLK
Transmit Data
Normal, No AIS
Transmit Clock (TCKO)
TCKI
0
0
0
0
1
1
0
0
0
1
0
1
0
1
AIS during TLOC
TI/EIACKI while TLOC
AIS During RLOS
AIS During TLOC or RLOS
Manual AIS
1
TCKI
1
TI/EIACKI while TLOC
X
X
TCKI
ACKI
Manual AIS and ACKI
NOTE(S): Systems that transmit framed all ones can utilize inband loopback code generator
[TLB; addr 077] to send all ones in payload only.
076—Transmit Test Pattern Configuration (TPATT)
Unused bits are reserved and should be written to 0.
7
6
5
4
3
2
1
0
—
—
—
TPSTART
FRAMED
ZLIMIT
TPATT[1]
TPATT[0]
TPSTART
FRAMED
Enable Test Pattern Transmission.
PRBS Framed—When set, the PRBS pattern does not overwrite framing bit positions and is
stopped during these bit periods. In T1 mode, the frame bit (every 193 bit) is not overwritten.
rd
In E1 mode, the PRBS test pattern is not written to time slot 0 (FAS and NFAS words) and
time slot 16 (CAS signalling word) if CAS framing is also selected. CAS framing is selected
by setting TFRAME[3] to 1 in the Transmit Configuration register [TCR0; addr 070]. If
FRAMED is disabled, the test pattern is transmitted in all time slots.
ZLIMIT
Enable Zero Limit; 7/14 depending on pattern.
TPATT[1:0]
PRBS test patterns used by RPATT [addr 041] and TPATT [addr 076] are defined in the ITU
standards O.151 and O.152 to use either inverted or non-inverted data. Standard data inversion
is used for the selected PRBS test pattern unless ZLIMIT is enabled, in which case the test
pattern uses non-inverted data (see Table 3-12).
100054E
Conexant
3-65
CONEXANT [ CONEXANT SYSTEMS, INC ]
